jorisvink / nyfe

A software based file encryption tool where all cryptographic parts are based on a single cryptographic permutation: Keccak-f[1600,24]. || This is a read-only mirror, pull requests are ignored.

Nyfe

A software based file encryption tool where all cryptographic parts are based on a single cryptographic permutation: Keccak-p[1600,24].

Nyfe is very minimal and lightweight as it has no external dependencies.

License

Nyfe is licensed under the ISC license.

Cryptography

WARNING: Nyfe uses experimental sponge-based cryptography.

Disclaimer

This is a personal research project of mine and at most it's a little broken.

You probably do not want to use this.

Confidentiality and Integrity

Its confidentiality and integrity are protected under Agelas.

Agelas is an experimental Authenticated Encryption stream cipher that is constructed with Keccak-f[1600,24] in combination with a duplex-sponge.

KDF

KMAC256 is used as a KDF for all derivations that take place.

KMAC256 is a NIST standard.

Random

The random system in Nyfe is also based on Keccak.

In this case, it will instantiate an Agelas context with keys that are derived from a random seed from the system which are run through KMAC256.

It then allows random byte generation of up to 960 bytes before rekeying itself.

An 64-byte ondisk entropy file under $HOME/.nyfe/entropy is mixed in if available, in addition to system entropy.

The entropy file is rewritten immediately when used. You're on your own to generate that file initially.

Keys

The keys used with Agelas are derived from strong 256-bit symmetrical secrets that are stored in key files.

Nyfe will generate a new key per file that is to be encrypted by selecting a seed uniformly at random and using it in combination with the symmetrical key from the given key file to derive new key material via KMAC256.

Metadata

The lack of meta-data in encrypted files is by design.

Performance

Performance is not considered at this stage, code correctness and extreme care in handling sensitive data was.

Building

Nyfe has been compiled on OpenBSD, MacOS 13.x and Ubuntu 22.04.

The only real dependency is a decent libc and compiler.

$ make
# make install

Tests

Nyfe includes the NIST SHA3 tests for SHA3-256, SHA3-512, SHAKE128 and SHAKE256.

You can run them on your machine by invoking the right target.

$ make clean
$ make keccak-tests

The inclusion of these tests are to verify that the underlying Keccak-p[1600,24] implementation is working correctly.

Usage

First, you'll want to initialize nyfe and generate the default keyfile:

$ nyfe init

You can generate another keyfiles as needed:

$ nyfe keygen $HOME/.nyfe/different.key

You can also clone keyfiles, as a means of exporting them with a different passphrase:

$ nyfe keyclone $HOME/.nyfe/different.key shared.key

Now you can encrypt some things with the default key:

$ nyfe encrypt myarchive.tar myarchive.nyfe

You can pipe straight into nyfe too if thats your thing:

$ tar zcv myarchive | nyfe encrypt -f $HOME/.nyfe/different.key myarchive.nyfe

You can also let nyfe output the encrypted data to stdout:

$ tar zcv myarchive | nyfe encrypt > myarchive.nyfe

Decrypting is pretty similar:

$ nyfe decrypt myarchive.nyfe myarchive.tar

You can also pipe into nyfe for decryption:

$ cat myarchive.nyfe | nyfe decrypt -f $HOME/.nyfe/different.key myarchive.tar

When decrypting Nyfe will refuse to output decrypted data to stdout since that is a security risk as the data output is not yet verified and Nyfe does not do chunks or intermediate tags.

Defaults

When encrypting or decrypting, the -f flag specifies what keyfile to use.

If the -f flag is omitted, Nyfe will use $HOME/.nyfe/secret.key by default.

Mascotte

Because mascottes are cool, here's SpongeNyfe: